diff mbox series

[V6,2/5] mailbox: Add support for QTI CPUCP mailbox controller

Message ID 20240612124056.39230-3-quic_sibis@quicinc.com (mailing list archive)
State Accepted
Commit 0e2a9a03106cd5fa0dbc9047675e7645c55e2669
Headers show
Series qcom: x1e80100: Enable CPUFreq | expand

Commit Message

Sibi Sankar June 12, 2024, 12:40 p.m. UTC 
Add support for CPUSS Control Processor (CPUCP) mailbox controller,
this driver enables communication between AP and CPUCP by acting as
a doorbell between them.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
---

v5:
* Fix build error reported by kernel test robot by adding 64BIT requirement
  to COMPILE_TEST

 MAINTAINERS                       |   7 ++
 drivers/mailbox/Kconfig           |   8 ++
 drivers/mailbox/Makefile          |   2 +
 drivers/mailbox/qcom-cpucp-mbox.c | 187 ++++++++++++++++++++++++++++++
 4 files changed, 204 insertions(+)
 create mode 100644 drivers/mailbox/qcom-cpucp-mbox.c

Comments

Bjorn Andersson June 26, 2024, 3:32 a.m. UTC | #1 
On Wed, Jun 12, 2024 at 06:10:53PM GMT, Sibi Sankar wrote:
> Add support for CPUSS Control Processor (CPUCP) mailbox controller,
> this driver enables communication between AP and CPUCP by acting as
> a doorbell between them.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>

Reviewed-by: Bjorn Andersson <andersson@kernel.org>

Regards,
Bjorn

> ---
> 
> v5:
> * Fix build error reported by kernel test robot by adding 64BIT requirement
>   to COMPILE_TEST
> 
>  MAINTAINERS                       |   7 ++
>  drivers/mailbox/Kconfig           |   8 ++
>  drivers/mailbox/Makefile          |   2 +
>  drivers/mailbox/qcom-cpucp-mbox.c | 187 ++++++++++++++++++++++++++++++
>  4 files changed, 204 insertions(+)
>  create mode 100644 drivers/mailbox/qcom-cpucp-mbox.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e04f583780c5..d7c00abe2f93 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18533,6 +18533,13 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/power/avs/qcom,cpr.yaml
>  F:	drivers/pmdomain/qcom/cpr.c
>  
> +QUALCOMM CPUCP MAILBOX DRIVER
> +M:	Sibi Sankar <quic_sibis@quicinc.com>
> +L:	linux-arm-msm@vger.kernel.org
> +S:	Supported
> +F:	Documentation/devicetree/bindings/mailbox/qcom,cpucp-mbox.yaml
> +F:	drivers/mailbox/qcom-cpucp-mbox.c
> +
>  QUALCOMM CPUFREQ DRIVER MSM8996/APQ8096
>  M:	Ilia Lin <ilia.lin@kernel.org>
>  L:	linux-pm@vger.kernel.org
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 3b8842c4a340..d1f6c758b5e8 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -276,6 +276,14 @@ config SPRD_MBOX
>  	  to send message between application processors and MCU. Say Y here if
>  	  you want to build the Spreatrum mailbox controller driver.
>  
> +config QCOM_CPUCP_MBOX
> +	tristate "Qualcomm Technologies, Inc. CPUCP mailbox driver"
> +	depends on ARCH_QCOM || (COMPILE_TEST && 64BIT)
> +	help
> +	  Qualcomm Technologies, Inc. CPUSS Control Processor (CPUCP) mailbox
> +	  controller driver enables communication between AP and CPUCP. Say
> +	  Y here if you want to build this driver.
> +
>  config QCOM_IPCC
>  	tristate "Qualcomm Technologies, Inc. IPCC driver"
>  	depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 5cf2f54debaf..3c3c27d54c13 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -61,4 +61,6 @@ obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
>  
>  obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
>  
> +obj-$(CONFIG_QCOM_CPUCP_MBOX)	+= qcom-cpucp-mbox.o
> +
>  obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
> diff --git a/drivers/mailbox/qcom-cpucp-mbox.c b/drivers/mailbox/qcom-cpucp-mbox.c
> new file mode 100644
> index 000000000000..e5437c294803
> --- /dev/null
> +++ b/drivers/mailbox/qcom-cpucp-mbox.c
> @@ -0,0 +1,187 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define APSS_CPUCP_IPC_CHAN_SUPPORTED		3
> +#define APSS_CPUCP_MBOX_CMD_OFF			0x4
> +
> +/* Tx Registers */
> +#define APSS_CPUCP_TX_MBOX_CMD(i)		(0x100 + ((i) * 8))
> +
> +/* Rx Registers */
> +#define APSS_CPUCP_RX_MBOX_CMD(i)		(0x100 + ((i) * 8))
> +#define APSS_CPUCP_RX_MBOX_MAP			0x4000
> +#define APSS_CPUCP_RX_MBOX_STAT			0x4400
> +#define APSS_CPUCP_RX_MBOX_CLEAR		0x4800
> +#define APSS_CPUCP_RX_MBOX_EN			0x4c00
> +#define APSS_CPUCP_RX_MBOX_CMD_MASK		GENMASK_ULL(63, 0)
> +
> +/**
> + * struct qcom_cpucp_mbox - Holder for the mailbox driver
> + * @chans:			The mailbox channel
> + * @mbox:			The mailbox controller
> + * @tx_base:			Base address of the CPUCP tx registers
> + * @rx_base:			Base address of the CPUCP rx registers
> + */
> +struct qcom_cpucp_mbox {
> +	struct mbox_chan chans[APSS_CPUCP_IPC_CHAN_SUPPORTED];
> +	struct mbox_controller mbox;
> +	void __iomem *tx_base;
> +	void __iomem *rx_base;
> +};
> +
> +static inline int channel_number(struct mbox_chan *chan)
> +{
> +	return chan - chan->mbox->chans;
> +}
> +
> +static irqreturn_t qcom_cpucp_mbox_irq_fn(int irq, void *data)
> +{
> +	struct qcom_cpucp_mbox *cpucp = data;
> +	u64 status;
> +	int i;
> +
> +	status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
> +
> +	for_each_set_bit(i, (unsigned long *)&status, APSS_CPUCP_IPC_CHAN_SUPPORTED) {
> +		u32 val = readl(cpucp->rx_base + APSS_CPUCP_RX_MBOX_CMD(i) + APSS_CPUCP_MBOX_CMD_OFF);
> +		struct mbox_chan *chan = &cpucp->chans[i];
> +		unsigned long flags;
> +
> +		/* Provide mutual exclusion with changes to chan->cl */
> +		spin_lock_irqsave(&chan->lock, flags);
> +		if (chan->cl)
> +			mbox_chan_received_data(chan, &val);
> +		writeq(BIT(i), cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
> +		spin_unlock_irqrestore(&chan->lock, flags);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int qcom_cpucp_mbox_startup(struct mbox_chan *chan)
> +{
> +	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
> +	unsigned long chan_id = channel_number(chan);
> +	u64 val;
> +
> +	val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
> +	val |= BIT(chan_id);
> +	writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
> +
> +	return 0;
> +}
> +
> +static void qcom_cpucp_mbox_shutdown(struct mbox_chan *chan)
> +{
> +	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
> +	unsigned long chan_id = channel_number(chan);
> +	u64 val;
> +
> +	val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
> +	val &= ~BIT(chan_id);
> +	writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
> +}
> +
> +static int qcom_cpucp_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> +	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
> +	unsigned long chan_id = channel_number(chan);
> +	u32 *val = data;
> +
> +	writel(*val, cpucp->tx_base + APSS_CPUCP_TX_MBOX_CMD(chan_id) + APSS_CPUCP_MBOX_CMD_OFF);
> +
> +	return 0;
> +}
> +
> +static const struct mbox_chan_ops qcom_cpucp_mbox_chan_ops = {
> +	.startup = qcom_cpucp_mbox_startup,
> +	.send_data = qcom_cpucp_mbox_send_data,
> +	.shutdown = qcom_cpucp_mbox_shutdown
> +};
> +
> +static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct qcom_cpucp_mbox *cpucp;
> +	struct mbox_controller *mbox;
> +	int irq, ret;
> +
> +	cpucp = devm_kzalloc(dev, sizeof(*cpucp), GFP_KERNEL);
> +	if (!cpucp)
> +		return -ENOMEM;
> +
> +	cpucp->rx_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
> +	if (IS_ERR(cpucp->rx_base))
> +		return PTR_ERR(cpucp->rx_base);
> +
> +	cpucp->tx_base = devm_of_iomap(dev, dev->of_node, 1, NULL);
> +	if (IS_ERR(cpucp->tx_base))
> +		return PTR_ERR(cpucp->tx_base);
> +
> +	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
> +	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
> +	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	ret = devm_request_irq(dev, irq, qcom_cpucp_mbox_irq_fn,
> +			       IRQF_TRIGGER_HIGH, "apss_cpucp_mbox", cpucp);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to register irq: %d\n", irq);
> +
> +	writeq(APSS_CPUCP_RX_MBOX_CMD_MASK, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
> +
> +	mbox = &cpucp->mbox;
> +	mbox->dev = dev;
> +	mbox->num_chans = APSS_CPUCP_IPC_CHAN_SUPPORTED;
> +	mbox->chans = cpucp->chans;
> +	mbox->ops = &qcom_cpucp_mbox_chan_ops;
> +
> +	ret = devm_mbox_controller_register(dev, mbox);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to create mailbox\n");
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id qcom_cpucp_mbox_of_match[] = {
> +	{ .compatible = "qcom,x1e80100-cpucp-mbox" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, qcom_cpucp_mbox_of_match);
> +
> +static struct platform_driver qcom_cpucp_mbox_driver = {
> +	.probe = qcom_cpucp_mbox_probe,
> +	.driver = {
> +		.name = "qcom_cpucp_mbox",
> +		.of_match_table = qcom_cpucp_mbox_of_match,
> +	},
> +};
> +
> +static int __init qcom_cpucp_mbox_init(void)
> +{
> +	return platform_driver_register(&qcom_cpucp_mbox_driver);
> +}
> +core_initcall(qcom_cpucp_mbox_init);
> +
> +static void __exit qcom_cpucp_mbox_exit(void)
> +{
> +	platform_driver_unregister(&qcom_cpucp_mbox_driver);
> +}
> +module_exit(qcom_cpucp_mbox_exit);
> +
> +MODULE_DESCRIPTION("QTI CPUCP MBOX Driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.34.1
>
Konrad Dybcio June 26, 2024, 9:43 a.m. UTC | #2 
On 12.06.2024 2:40 PM, Sibi Sankar wrote:
> Add support for CPUSS Control Processor (CPUCP) mailbox controller,
> this driver enables communication between AP and CPUCP by acting as
> a doorbell between them.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>

Konrad
Nathan Chancellor July 15, 2024, 3:14 a.m. UTC | #3 
Hi Sibi,

On Wed, Jun 12, 2024 at 06:10:53PM +0530, Sibi Sankar wrote:
> Add support for CPUSS Control Processor (CPUCP) mailbox controller,
> this driver enables communication between AP and CPUCP by acting as
> a doorbell between them.
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
> ---
> 
> v5:
> * Fix build error reported by kernel test robot by adding 64BIT requirement
>   to COMPILE_TEST
...
> +config QCOM_CPUCP_MBOX
> +	tristate "Qualcomm Technologies, Inc. CPUCP mailbox driver"
> +	depends on ARCH_QCOM || (COMPILE_TEST && 64BIT)

This doesn't work, ARCH=arm allmodconfig is still broken with:

  drivers/mailbox/qcom-cpucp-mbox.c: In function 'qcom_cpucp_mbox_irq_fn':
  drivers/mailbox/qcom-cpucp-mbox.c:54:18: error: implicit declaration of function 'readq'; did you mean 'readb'? [-Wimplicit-function-declaration]
     54 |         status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
        |                  ^~~~~
        |                  readb
  drivers/mailbox/qcom-cpucp-mbox.c:65:17: error: implicit declaration of function 'writeq'; did you mean 'writel'? [-Wimplicit-function-declaration]
     65 |                 writeq(BIT(i), cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
        |                 ^~~~~~
        |                 writel

because there is ARCH_QCOM for that architecture as well.

You could resolve this by just including either io-64-nonatomic-hi-lo.h
or io-64-nonatomic-lo-hi.h or shuffling the dependencies to require
64BIT unconditionally:

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index d1f6c758b5e8..8d46b76c23fd 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -278,7 +278,7 @@ config SPRD_MBOX
 
 config QCOM_CPUCP_MBOX
 	tristate "Qualcomm Technologies, Inc. CPUCP mailbox driver"
-	depends on ARCH_QCOM || (COMPILE_TEST && 64BIT)
+	depends on 64BIT && (ARCH_QCOM || COMPILE_TEST)
 	help
 	  Qualcomm Technologies, Inc. CPUSS Control Processor (CPUCP) mailbox
 	  controller driver enables communication between AP and CPUCP. Say

Cheers,
Nathan
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e04f583780c5..d7c00abe2f93 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18533,6 +18533,13 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/power/avs/qcom,cpr.yaml
 F:	drivers/pmdomain/qcom/cpr.c
 
+QUALCOMM CPUCP MAILBOX DRIVER
+M:	Sibi Sankar <quic_sibis@quicinc.com>
+L:	linux-arm-msm@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/mailbox/qcom,cpucp-mbox.yaml
+F:	drivers/mailbox/qcom-cpucp-mbox.c
+
 QUALCOMM CPUFREQ DRIVER MSM8996/APQ8096
 M:	Ilia Lin <ilia.lin@kernel.org>
 L:	linux-pm@vger.kernel.org
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 3b8842c4a340..d1f6c758b5e8 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -276,6 +276,14 @@  config SPRD_MBOX
 	  to send message between application processors and MCU. Say Y here if
 	  you want to build the Spreatrum mailbox controller driver.
 
+config QCOM_CPUCP_MBOX
+	tristate "Qualcomm Technologies, Inc. CPUCP mailbox driver"
+	depends on ARCH_QCOM || (COMPILE_TEST && 64BIT)
+	help
+	  Qualcomm Technologies, Inc. CPUSS Control Processor (CPUCP) mailbox
+	  controller driver enables communication between AP and CPUCP. Say
+	  Y here if you want to build this driver.
+
 config QCOM_IPCC
 	tristate "Qualcomm Technologies, Inc. IPCC driver"
 	depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 5cf2f54debaf..3c3c27d54c13 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -61,4 +61,6 @@  obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
 
 obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
 
+obj-$(CONFIG_QCOM_CPUCP_MBOX)	+= qcom-cpucp-mbox.o
+
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
diff --git a/drivers/mailbox/qcom-cpucp-mbox.c b/drivers/mailbox/qcom-cpucp-mbox.c
new file mode 100644
index 000000000000..e5437c294803
--- /dev/null
+++ b/drivers/mailbox/qcom-cpucp-mbox.c
@@ -0,0 +1,187 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define APSS_CPUCP_IPC_CHAN_SUPPORTED		3
+#define APSS_CPUCP_MBOX_CMD_OFF			0x4
+
+/* Tx Registers */
+#define APSS_CPUCP_TX_MBOX_CMD(i)		(0x100 + ((i) * 8))
+
+/* Rx Registers */
+#define APSS_CPUCP_RX_MBOX_CMD(i)		(0x100 + ((i) * 8))
+#define APSS_CPUCP_RX_MBOX_MAP			0x4000
+#define APSS_CPUCP_RX_MBOX_STAT			0x4400
+#define APSS_CPUCP_RX_MBOX_CLEAR		0x4800
+#define APSS_CPUCP_RX_MBOX_EN			0x4c00
+#define APSS_CPUCP_RX_MBOX_CMD_MASK		GENMASK_ULL(63, 0)
+
+/**
+ * struct qcom_cpucp_mbox - Holder for the mailbox driver
+ * @chans:			The mailbox channel
+ * @mbox:			The mailbox controller
+ * @tx_base:			Base address of the CPUCP tx registers
+ * @rx_base:			Base address of the CPUCP rx registers
+ */
+struct qcom_cpucp_mbox {
+	struct mbox_chan chans[APSS_CPUCP_IPC_CHAN_SUPPORTED];
+	struct mbox_controller mbox;
+	void __iomem *tx_base;
+	void __iomem *rx_base;
+};
+
+static inline int channel_number(struct mbox_chan *chan)
+{
+	return chan - chan->mbox->chans;
+}
+
+static irqreturn_t qcom_cpucp_mbox_irq_fn(int irq, void *data)
+{
+	struct qcom_cpucp_mbox *cpucp = data;
+	u64 status;
+	int i;
+
+	status = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_STAT);
+
+	for_each_set_bit(i, (unsigned long *)&status, APSS_CPUCP_IPC_CHAN_SUPPORTED) {
+		u32 val = readl(cpucp->rx_base + APSS_CPUCP_RX_MBOX_CMD(i) + APSS_CPUCP_MBOX_CMD_OFF);
+		struct mbox_chan *chan = &cpucp->chans[i];
+		unsigned long flags;
+
+		/* Provide mutual exclusion with changes to chan->cl */
+		spin_lock_irqsave(&chan->lock, flags);
+		if (chan->cl)
+			mbox_chan_received_data(chan, &val);
+		writeq(BIT(i), cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
+		spin_unlock_irqrestore(&chan->lock, flags);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int qcom_cpucp_mbox_startup(struct mbox_chan *chan)
+{
+	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+	unsigned long chan_id = channel_number(chan);
+	u64 val;
+
+	val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+	val |= BIT(chan_id);
+	writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+
+	return 0;
+}
+
+static void qcom_cpucp_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+	unsigned long chan_id = channel_number(chan);
+	u64 val;
+
+	val = readq(cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+	val &= ~BIT(chan_id);
+	writeq(val, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+}
+
+static int qcom_cpucp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct qcom_cpucp_mbox *cpucp = container_of(chan->mbox, struct qcom_cpucp_mbox, mbox);
+	unsigned long chan_id = channel_number(chan);
+	u32 *val = data;
+
+	writel(*val, cpucp->tx_base + APSS_CPUCP_TX_MBOX_CMD(chan_id) + APSS_CPUCP_MBOX_CMD_OFF);
+
+	return 0;
+}
+
+static const struct mbox_chan_ops qcom_cpucp_mbox_chan_ops = {
+	.startup = qcom_cpucp_mbox_startup,
+	.send_data = qcom_cpucp_mbox_send_data,
+	.shutdown = qcom_cpucp_mbox_shutdown
+};
+
+static int qcom_cpucp_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct qcom_cpucp_mbox *cpucp;
+	struct mbox_controller *mbox;
+	int irq, ret;
+
+	cpucp = devm_kzalloc(dev, sizeof(*cpucp), GFP_KERNEL);
+	if (!cpucp)
+		return -ENOMEM;
+
+	cpucp->rx_base = devm_of_iomap(dev, dev->of_node, 0, NULL);
+	if (IS_ERR(cpucp->rx_base))
+		return PTR_ERR(cpucp->rx_base);
+
+	cpucp->tx_base = devm_of_iomap(dev, dev->of_node, 1, NULL);
+	if (IS_ERR(cpucp->tx_base))
+		return PTR_ERR(cpucp->tx_base);
+
+	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_EN);
+	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_CLEAR);
+	writeq(0, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(dev, irq, qcom_cpucp_mbox_irq_fn,
+			       IRQF_TRIGGER_HIGH, "apss_cpucp_mbox", cpucp);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register irq: %d\n", irq);
+
+	writeq(APSS_CPUCP_RX_MBOX_CMD_MASK, cpucp->rx_base + APSS_CPUCP_RX_MBOX_MAP);
+
+	mbox = &cpucp->mbox;
+	mbox->dev = dev;
+	mbox->num_chans = APSS_CPUCP_IPC_CHAN_SUPPORTED;
+	mbox->chans = cpucp->chans;
+	mbox->ops = &qcom_cpucp_mbox_chan_ops;
+
+	ret = devm_mbox_controller_register(dev, mbox);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to create mailbox\n");
+
+	return 0;
+}
+
+static const struct of_device_id qcom_cpucp_mbox_of_match[] = {
+	{ .compatible = "qcom,x1e80100-cpucp-mbox" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_cpucp_mbox_of_match);
+
+static struct platform_driver qcom_cpucp_mbox_driver = {
+	.probe = qcom_cpucp_mbox_probe,
+	.driver = {
+		.name = "qcom_cpucp_mbox",
+		.of_match_table = qcom_cpucp_mbox_of_match,
+	},
+};
+
+static int __init qcom_cpucp_mbox_init(void)
+{
+	return platform_driver_register(&qcom_cpucp_mbox_driver);
+}
+core_initcall(qcom_cpucp_mbox_init);
+
+static void __exit qcom_cpucp_mbox_exit(void)
+{
+	platform_driver_unregister(&qcom_cpucp_mbox_driver);
+}
+module_exit(qcom_cpucp_mbox_exit);
+
+MODULE_DESCRIPTION("QTI CPUCP MBOX Driver");
+MODULE_LICENSE("GPL");